On Spread Spectrum for DC Grids: Low-Frequency Conducted EMI Mitigation and Signal Integrity Disruption in Serial Communication Links

Abstract

This article addresses the effects on nearby communication systems when spread spectrum modulation techniques are used for a dc-dc power converter. These interactions can be found in modern smart grids and automotive power networks in which the combination of communication links, switching power supplies, and long cables play a major role in electromagnetic interference issues at low frequencies below 150 kHz. Spread spectrum modulation, with its different variations (sine and random) are widely used to comply with electromagnetic compatibility standards. However, there are certain effects that can be harmful to either the converter or the rest of the power network. These effects happen at different frequencies and for different parameters used in the modulation algorithm. With the aim to standardize an assessment procedure, measurements are made to determine the interference created by an SiC-based dc-dc converter. The peak index of a CISPR-16 EMI receiver is used to evaluate the behavior in the frequency domain while a study in serial communication disruption is undertaken using mean and quantile values from a bit error rate tester.